A small team of American Special Operations forces, armed with intelligence recovered during the arrest of Khalid Shaikh Mohammed, has been dispatched to the border region between Pakistan and Afghanistan in an attempt to find Osama bin Laden, government officials said today.

The search unit has so far failed to determine the whereabouts of the leader of Al Qaeda, the officials said, adding that they remain hopeful that the long search for Mr. bin Laden, who slipped away in December 2001 during a battle with American forces in Afghanistan, may be near an end.

But with no progress to report, American officials tried today to ratchet down expectations of an immediate capture of Mr. bin Laden. Hopes had soared after the arrest of Mr. Mohammed last Saturday in Rawalpindi, Pakistan.

With the American team still in the region, Pakistan has reinforced its own heavy presence in the border region with additional troops, an American official said. The Pakistani troops are being sent to aid in the search and provide a barrier to prevent an escape by Mr. bin Laden and his entourage of aides and security personnel.

Pakistani officials said that troops are searching at several places in southwestern Pakistan. One is near the point where the borders of Iran, Pakistan and Afghanistan join. Another is along the border of Pakistan and Afghanistan at Chagai, and a third is near Spinboldak, on the main border crossing between Baluchistan and Afghanistan.

But American intelligence and military officials denied that any new or large-scale operations were underway. Instead, the main search effort seemed to be by small groups of highly trained American troops who have moved quickly to specific sites looking for Mr. bin Laden. The officials said that the team had to deploy rapidly because the information was specific and suggested where the Qaeda leader would be found at a particular point in time.

At the same time, along a wide swath of Pakistan's border regions today, residents reported leaflets fluttering to earth reminding finders of a $25 million reward for information leading to the apprehension of Mr. bin Laden.

With conflicting reports from the region about the status of the search for Mr. bin Laden, a Pakistani government spokesman, Maj. Gen. Rashid Qureshi, categorically denied today that there had been any step up in the search for the terrorist leader since Mr. Mohammed's arrest.

''Nonsense, nonsense,'' General Qureshi said about reports that American and Pakistani forces were working together to find Mr. bin Laden. Not only were American special forces not ''pouring in,'' as some news reports have said, but they were not even ''drip, drip, drip, dripping in.''

General Qureshi did say, however, that there has been a small team of Americans, maybe 12 people, whom he called ''electronic intelligence experts,'' working with Pakistani intelligence in remote tribal regions along the border with Afghanistan.

At the same time, the police in Baluchistan were told to prepare for a possible operation, Pakistani officials said. This suggests that an arrest could be made in that area of Pakistan, they said, where intelligence of both countries has sometimes placed Mr. bin Laden in the past.

The possibility that Mr. bin Laden might be found has led to a debate among some officials in Pakistan over whether, if cornered, Mr. bin Laden will put up a ''grand stand,'' as one official put it and go down in history as a martyr, or whether he will surrender.

Capturing him will not be easy, said another Pakistani official who is part of the search. ''He is surrounded by a bunch of die-hard, committed and well-trained comrades.''

While the exact extent of operations underway in the search for Mr. bin Laden remained somewhat uncertain, it was evident that the arrest of Mr. Mohammed a week ago had accelerated the investigation.

Officials said today that investigators continued to pore over the evidence obtained during the arrest of Mr. Mohammed in Rawalpindi -- enough material, they said to fill a small government jet. The information also turned up more leads in the United States.

Many of the names of people in the United States were already known to the F.B.I., officials said. But the evidence from the arrest has led to inquiries from New York to California. But so far, no arrests have been made that were based on the new evidence.

In New York, officials said they were investigating three men, one each from Long Island, Westchester and New York City. It remained unclear how they were connected to Mr. Mohammed and whether they were engaged in planning any terrorist plots.

One senior official said that the name of another mid-level Qaeda operative was found among the materials in the house where Mr. Mohammed was arrested. The information suggested that the man was on the West Coast, but when agents pursued the lead they discovered the subject had left the United States long ago.

American officials disputed news accounts saying that Mr. Mohammed, the senior Qaeda operations chief, had predicted to Pakistani authorities before he was turned over to the United States that there would be terrorist attacks against American forces gathering in the Persian Gulf if the United States commenced military action against Iraq.

But the officials said that, apart from any comments by Mr. Mohammed, they believe there is a strong possibility of reprisal attacks. They added that they have detected no upsurge in the level or seriousness of threat reports against American interests in the Persian Gulf region since Mr. Mohammed's arrest.

The White House cast doubt today on reports from Pakistan that two sons of Osama bin Laden were wounded and possibly arrested by United States and Afghan troops operating in Afghanistan. ''We have no information to substantiate that report,'' said Ari Fleischer, the White House spokesman.